Telegraph system.



J. H. BELL.

TELEGRAPH SYSTEM. APPLICATION FILED JULY 12.1917.

Patented May 14, 1918.

sar s rnrniar enrich some nuns BELL, or user cannon, new innsnr, ASSIGNOB. ro wns'rnnn nrnornro conrraivr, rnconrona'rnn, or new roan, n. Y., a oonronarron or new roan TELEGRAPH SYSTEM.

Specification of Letters Patent. I Patented May 14;, 3.918.

Application filed m 12, i917. Serial in. 180,168.

ceiving apparatus and systems for reproducing telegraphic signals in the form of a printed record.

The-object of this invention to providea telegraph receiver capable of performing the necessary functions in a reliable and er"- ficient manner to render service of particular value in connection with line conductors having low time constant characteristics as in submarine cable working.

This invention provides a line relay responsive to alternating current impulses and adapted selectively to close difi'erent contacts, depending upon the amplitude of the received current. These contacts in turn control the circuits of a group of selectively operated selecting relays, a distributor beingprovided for completing the circuits from the line relay to the selecting relays sequentially in synchronism with the receipt of the line signals.

The present receiving equipment preferably responds to telegraphic signals formed of three-unit code impulses comprising three successive alternations or one-half cycle currents formed from combinations of currents of predetermined strength and first and second incremented values thereof. A suitable arrangement not shown but well understood in the art is to be employed for driving the distributer in such phase with incoming impulses from the line, .that in unison with each impulse the distributor will be effective over certain radially associated pairs of segment contacts.

This invention is illustrated in the accompanying drawing, in which only so much of a telegraph receiving. equipment is shown as will be necessary for a clear understandingof this system. Figure 1 is a diagrammatic illustration of a preferred embodimentof this invention, while Fig. 2 similarly illustrates an alternative arrangement.

Referring to the drawing, the selective action set up by a. combination of three-unit code impulses will be traced, as such descriptions will be suiiicient to afiord a clear understanding of the feature of the present system. I

For convenience let it be assumed that a three-unit code signal formed of an alternation of minimum current strength and positive polarity, an. alternation of negative polarity incremented to a mean current strength,

and analternation of positive polarity incremented to a maximum current strength suitable for selecting a letter, say F, will be received over a line conductor 1. Accordingly, the first weak-impulse of current on traversing a primary winding 3 of a transformer fl to a ground connection 2 sets up a corresponding current action in the secondary winding 5 of the transformer. A mov ing coil 11 of a gold wire relay 10 (of Wellknown type) included with the secondary winding 5, although afiected by this weak current impulse is not suificiently stressed to cause a gold wire tongue 12 (moved by a physical connection with the coil 11 not shown) to move with suficient amplitude to against the right-hand prong of the contact 16. The arm 21 of the distributer 2O moving in step with the impulses of current from the line 1 will at the same moment be present over the segments 50 and 60, there by completing a circuit prepared by the relay 1(). This circuit extends from a source 8, current bus 9, contacts 12 and 16 of the relay l0, conductor 17, contactor rin 27 of the distributer 20, brush 22 carried y the trailer arm 21, segment 60, conductor 61, contacts 57 of a relay 52, the winding of a relay 62 to a current bus 7, common to the opposite side of the current supply 8. The relay 62 operates and completes a circuit from current bus 7., contacts 64 of this relay 66 (contact membersof which are'not.

shown), to the opposite bus conductor 9.

Passing now to the third and strongest pulse or positive current from the line conductor 1, current-action through the transformer l exerts suficient force on the onerating coil ll of the relay 10 to loring the tongue 12 first against the left-hand prong? of the contact 16 and thereafter to flex or bend it sufiiciently to also make contact with the left-hand prone; oi the contact 14-. .Since the current has 9 connects to the tongue 12 it follows that current therefrom will pass over the contacts l t and 16 and conductors l5 and 1? respectively to energize the contact-or rings 25 and 2'? of the distributor 2%), The trailer arm 21 now over the segments I and 80 completes a circuit from the ring 25, brush E23, segment 70 conductor llythewinrh ing of a r lay 72, to the current bus '2'. The relay 72 thereby operated completes a circuit through its contacts re from the lons'l, condoctor 75, and the winding of a relay 76 to the current bus 9. A further result of the operation of the relay 72 is the separation oft its contacts 77 to disable a relay which this time would otherwise heoperated by current from the ring 27 of the distributor traversing a brush E22 carried by but insulated from the arm 21, and segment $0 to a conductor 8i which now stands disconnected at the contacts '1? 'l of the relay it will he clear the action resnlting cm the impulses of current just described estahlishes the operation of relays 62 '32, 66 and to, and through other responsive means (not shown) such action sheets the final selection and printing of the letter F. At

though not shown, it wiloe understood that suitable contact i einhers he carried the relay coils so 56, '66 t and as. such contact rnemoers control selection responsive means whereby sary operations or rece n v nrst, strength do not st pound acting rela 1 second, that currents of sing or mean strengths close only 1 I the relay 10 to energize ciated with the segments the distributor 2G; an oi we-step or two-tore value close both contacs thereby energize each distributor. l t will he not although both or the distributor may he ener fi same time only one i the relay 10 to 5 and 21 or the -formed respectively o 3'2 82; e o

relays as, 62 and 82.

Referring to the alternate arrangement shown in Figxfi of the drawing, this rhodif'lcation difiers from the first in that only one contactor ring and one set of associated segments 30, 50 and l0 are required on the distributor 20. carrying out this change it will he noted that the current source is included between the tongue 12 of the relay 10 and the ring 25 of the distributor, while the contacts 1% and 18 of the relay 10 are included respectively with the one conductors of relays 82, 52 and '72 and relay 4%, 62 and 82. impulse from the line l to connect the gold wire with the contact 16 of the relay l0, circuit is thereby prepared from current source 8 through each relay as, "62 and 82 to the respectively associated seements on the distributor, The synchronizing of the distriloilter 20 three-unit code impulses described for the first arrangement results in the trailer arm 21 being over one or another of these segments during the action of an irnlonlsel That is, for a first inioulse a three-unit code the trailer d be over segment 3d; for a second imm segment 5G; and for a the trailer arrn :21

with respect to the segment 30 5G or W.

For a douloly incremented current impulse from the line l. wherehy naeniloer l oi the relay r0 completes circuit with hoth contacts and 1' thereby energizing the relay hnses nd 7, the trailer arm 21 may UJec' oer relay 32 52 or L4, since ntacts 37 7'? of these relays ely the relays 42 62 852. event stray or momentary or carrent arresting the last-reenrelays during a time circuit is coinone of common conducit will he understood or adjustment the relays m y he adapted to respond than the relays 12 62 and EH iveiy slow inan- Accordingly for an he segment 70. it will, thereion rangement whereby the contacts of the relays 42, 62 and 82 are adapted to in turn 0 erate other relays or electroresponsive evices (not shown) afi'ords a sufiicient socalled bug-trap guard to prevent interference in case all of the relays are of the same type or adjusted to the same operating char acteristics.

Although a gold wire relay has for convenience been shown in connection with this invention, a suitable relay of other type may be readily substituted therefor.

For multiplex working a second receiving equipment similar to the present invention may be employed in connection with the three uppermost pairs of idle segments on the distributer 20. And also, in a suitable situation, a transmitting equipment may be substituted for the second transmitter and employed to work a receiving equipment at the distant end of the line circuit.

What is claimed is:

-1. In a telegraph system wherein the different characters of a message are represent ed by different combinations of alternating current impulses of various strengths, 3. line relay selectively responsive to impulses of different strength, in combination with a plurality of pairs of selecting relays, and distributer means for successively connecting said line relay to said pairs of selecting relays. I

2. In a telegraph system wherein the different characters of a message are repre sented by difierent combinations of alternating current impulses of various strengths, a line relay selectively responsive to impulses of different strengths, in combination with a plurality of selecting relays selectively responsive to the selective actuation of said line relay, and distributer means for successively connecting said line relay to said selecting relays.

3. In a telegraph system, a selectively responsive line relay, a plurality of relays associated in pairs, a distributer for including said relays in pairs with said line relay, and contacts controlled by a relay in each of said pairs of relays to disable the other relay of a pair.

4. In a telegraph system, a line relay selectively responsive to alternating currents of various strengths, a plurality of selecting relays associated in pairs, a distributer for selectively including said pairs ofrelays to permit an individual relay to be selected by said line relay, and switching means controlled by said distributer to prevent stray momentary currents from afi'ecting the nonselected relay of a pair.

In witness whereof, I hereunto subscribe my name this 10th day of July, A. I). 1917.

JOHN HUME BELL. 

